Certain genera have undergone massive diversification — the 10 largest genera account for 21.5 percent of the flora — with the two most speciose being Erica (Ericaceae: 658 species) and Aspalathus (Fabaceae: 257 species).

Miombo woodland is distinguished from other African savanna, woodland, and forest formations by the dominance of tree species in the family Fabaceae, subfamily Caesalpinioideae, particularly in the genera Brachystegia, Julbernardia, and Isoberlinia which are seldom found outside miombo.